An intravenous (IV) system typically includes a bag holding the fluids to be infused, tubes connecting the bag to the patient and a pump to regulate the flow of fluids into the patient. Such pumps are utilized for providing many types of fluid, chemotherapy being but one example.
The chemicals for chemotherapy are typically very expensive and very toxic. This requires that minimal amounts of the chemicals be wasted and that the medical staff, who are generally healthy, not be exposed to the toxic drugs. Unfortunately, current pump technology does not ensure this.
The problem is that the toxic fluids generate air as they move through the IV tubes and only a small amount of air may be introduced into a patient's bloodstream. Current pumps have an air bubble detector, to detect the presence of air (as an air bubble) and to stop the operation of the pump as a result of a small amount of air (for example, 1 ml) passing to the patient within a pre-defined period of time (such as 15 min) or single bubbles that are more than a pre-determined size (0.2 ml as an example). The pump then alerts the medical staff, which detaches the tubes, refills them with fluid (usually by spilling some of the fluid into a container of some kind) removing the air bubbles in the process and restarts the pump. Unfortunately, patients receiving chemotherapy are very sensitive to contamination, which may happen when the tubes are detached.
Moreover, this procedure can expose the medical staff to the toxic fluids and air and it spills the expensive drugs. Moreover, detaching the tubes exposes them and can lead to contamination of the patient. Another issue is that the air bubbles tend to stop treatment in short intervals.
The following patent publications discuss various attempts to solve these problems, including adding traps for air in the pump and after the pump: U.S. Pat. No. 7,131,966 to Tamari, U.S. Pat. No. 4,954,256 to Degen et al, US 2002/0056675 to Hegde, U.S. Pat. No. 6,280,408 to Sipin, U.S. Pat. No. 5,308,333 to Skakoon, U.S. Pat. No. 7,048,720 to Thorne, Jr. et al and U.S. Pat. No. 4,927,411 to Pastrone et al.